I was not able to post a picture yet because I am a new member. Mine are similar to the picture from Robo. They have 4" axial fans mounted on the bottom of the box, with screened damper vents on the end, powered by a 5A solar panel mounted high, and a temp switch that comes on at 90' F. It sure saves time for the bees to scavage for more honey & pollen. It helps dry out the moisture in the honey, and the girls do not have to spend all their time fanning the entrance and brood.